I bought this game 'cause I thought the world would be open and stay open. Now all the action is put into instances because SE servers can't handle an open world (at least that's how it seems to me). I played GW since beta and now I'm pretty tired of instanced stuff :P
It's entertaining to enter a dungeon and see other parties getting beat up by mobs that you trained to them <.<
Not as funny if you do that to your own party... but no choice if yours is the only party in the area